Pressure-sensitive adhesives are extensively used in masking tapes, double-faced pressure-sensitive adhesive tapes, surface-protective films, packaging tapes, and the like. Developments in pressure-sensitive adhesives of the aqueous dispersion type containing no organic solvent have hitherto been proceeding from the standpoints of a measure for environmental protection, resource saving, safety, etc., and the amount of the aqueous dispersion type pressure-sensitive adhesives to be used tends to increase. Of such aqueous dispersion type pressure-sensitive adhesives, rubber-based pressure-sensitive adhesives of the aqueous dispersion type have advantages such as reduced limitations on adherend selection and excellent low-temperature adhesiveness and are hence presently used most extensively. Acrylic pressure-sensitive adhesives of the aqueous dispersion type are coming to be widely used in place of the existing rubber-based pressure-sensitive adhesives of the aqueous dispersion type because of their excellent adhesive properties, weatherability, etc.
On the other hand, masking tapes, for example, have had the following problem. When a masking tape, which is a tape for masking adherends in painting, sealing, or the like, is applied in the rainy season or low-temperature winter season to an adherend surface where dew condensation has occurred, there are cases where sufficient adhesive force cannot be obtained in the application and tape shifting or peeling occurs, leading to reduced applicability. Double-faced pressure-sensitive adhesive tapes and the like also have had the same problem in application to dewy surfaces.
A pressure-sensitive adhesive tape containing a water-soluble polymer as a major component has been disclosed as an adhesive tape having satisfactory adhesiveness to dewy surfaces. However, satisfactory results have not been obtained therewith, for example, because low-molecular components which have been dissolved away as a result of water absorption/swelling cause fouling upon peeling and the pressure-sensitive adhesive has insufficient cohesive force and hence leaves an adhesive residue upon peeling.